What is the best way to create an activity that will target only the affected zip codes?

One of the distribution centers for an eCommerce site is down and the marketing team wants to display a message on the homepage to let customers know that shipping will be delayed.

What is the best way to create an activity that will target only the affected zip codes?
A . Create an A/B test, then create a custom audience for the test experience and make a rule in Geo with the list of zip codes.
B . Create an A/B test, then create a custom audience for the test experience and make a rule in Geo with the list of zip codes. Divert 100% of traffic to the test experience.
C . Create an XT activity, then create a custom audience and make a rule in Geo with the list of zip codes.

Answer: C